Premixer for low emissions gas turbine combustor

A dual fuel premixer comprising:

• a centerbody disposed along a longitudinal axis of the dual fuel premixer, the centerbody defining a fuel passage therethrough and a plurality of fuel ports in communication with the fuel passage and defined through a centerbody wall;
• a swirler assembly comprising:
• a hub circumferentially surrounding a portion of the centerbody upstream of the plurality of fuel ports;
• an annular splitter circumferentially surrounding and radially outward of the hub;
• an outer ring circumferentially surrounding and radially outward of the annular splitter, the outer ring defining a primary fuel plenum therein;
• a first array of inner swirler vanes extending between the hub and the annular splitter to impart swirl in a first direction to a flow of incoming air;
• and
• a second array of outer swirler vanes extending between the annular splitter and the primary fuel plenum to impart swirl in a second direction opposite the first direction to the flow of incoming air, each outer swirler vane of the second array defining at least one fuel metering hole therein in fluid communication with the primary fuel plenum, the second array of outer swirler vanes defining an outlet plane;
• and
• a mixing duct extending downstream from the primary fuel plenum, the mixing duct defining a mixing chamber configured to promote mixing of the flow of incoming air and fuel,
• wherein each inner swirler vane of the first array has a first portion connected to the hub and a second portion connected to the annular splitter, the first portion being longer than the second portion, such that an oblique angle is defined between a trailing edge of each inner swirler vane and the outlet plane of the second array of outer swirler vanes.